This thesis investigates the continuity of Wittgenstein’s approach to, and conception of, philosophy. Part One examines the rule-following passages of the Philosophical Investigations. I argue that Wittgenstein’s remarks can only be read as interesting and coherent if we see him, as urged by prominent commentators, resisting the possibility of a certain ‘sideways-on’ perspective. There is real difficulty, however, in ascertaining what the resulting Wittgensteinian position is: whether it is position structurally analogous with Kant’s distinction between empirical realism and transcendental idealism, (...) or whether philosophical ‘therapy’ is meant to dissolve any drive towards such idealism. I argue that both of these readings of Wittgenstein are found in the work of McDowell. Part Two argues that related issues arise in respect to the Tractatus Logico-Philosophicus and the question of realism. In the Tractatus Wittgenstein rejects the possibility of a certain ‘sideways-on’ perspective. Again, I argue, it is unclear whether Wittgenstein embraces a form of transcendental idealism or, on the contrary, ultimately reveals the idealist position to be empty. Part Three connects ‘sideways-on’ glances with the threat of idealism by introducing a philosophical ‘measure’. I argue that the measure is a useful tool in assessment of the Tractatus, and shows that Wittgenstein was no idealist, but is less useful as an assessment of the Investigations. It yields the result that Wittgenstein succumbed to idealism, but in doing so may overlook the ‘therapeutic’ nature of Wittgenstein’s later philosophy. (shrink)